The translation of "défunte" as "dead" is a bit misleading; a more accurate but less catchy title might be "Pavane for a princess from long ago" or "of antiquity". When the piece became a top-40 of the parlors and salons of ImpressionistFrance in 1899, surely some of its intrigue arose from the somber title and the story it implies - but compositeur extraordinaire Joseph-Maurice Ravel would repeatedly insist that he simply liked how the words fit together: the piece was not “about” any particular ex-infanta. He described the piece as "a slow Spanish dance to which a little princess may once have danced," and certainly not intended as elegiac. An admiration of Spanish aesthetic and culture was actually common at the time - shared by many of Ravel's contemporaries (such as Debussy) and evident in a number of Ravel's otherworks.

Whatever the intent of the title, the music seems to mean something a bit more than pastiche to a lot of people. Perhaps it'd be worth your time to give it a listen?*

Ravel was still in school studying under Gabriel Fauré when he composed the piece (in fact, as an assignment) - but his style is already unmistakable here: lush but lucid harmonically, poignant and crystalline melodically, with a complex, dancelike touch and sensitivity to timbre. The work became so popular he produced an orchestral arrangement in 1910. Later in his life, though, Ravel would distance himself from the work, feeling it overly conventional - "lacking daring".